Ellsworth Kelly. Apples. Paris, 1949. Pencil on paper, 17 x 22 1/8" (43.4 x 56.4 cm), MoMA. contour line: describes the visible, outer and inner edges of a form, mass, figure or object; may suggest space, depth, weight, light, shadow, etc. "When you draw lines curving around the surface, or contour, of an object, you give that object volume. You make that object appear to be popping out of the paper." Mark Kistler.